#define  _CRT_SECURE_NO_WARNINGS 1		
#include <stdio.h>
#include<math.h>
int main() {
    double a;
    long b;
    while (scanf("%lf %ld", &a, &b) != EOF)
    {
        double sum = 0;
        for (int i = 0; i < b; i++)
        {
            sum += a;
            a = sqrt(a);
        }
        printf("%.2lf\n", sum);
    }

    return 0;
}